Detergent composition

ABSTRACT

A cleaning composition comprising (1) at least one of fluoride salts and hydrogendifluoride salts; (2) an organic solvent having a hetero atom or atoms; and (3) water; a method of cleaning metal gate, contact hole, via hole and capacitor using the composition; a method of cleaning a residual polymer derived from a resist using the composition; and a method of cleaning after CMP using the composition.

TECHNICAL FIELD

The present invention relates to a cleaning composition for use in theprocess of producing a semiconductor. Specifically the invention relatesto a composition which can be used in cleaning a metal gate, a contacthole, a via hole, a capacitor or the like, in removing a polymer derivedfrom a resist and in cleaning after CMP. More specifically, theinvention relates to a cleaning composition which can be suitably usedin producing a semiconductor device or a liquid crystal panel devicesuch as IC, LSI or the like.

BACKGROUND ART

Conventionally poly-Si has been used as a material for a gate electrodein a semiconductor device. With microminiaturization, there is apossibility of using tungsten, copper, aluminum or like metals as amaterial for a gate electrode. Now SPM (H₂SO₄—H₂O₂—H₂O), APM(NH₄OH—H₂O₂—H₂O), HPM(HCl—H₂O₂—H₂O), DHF(HF—H₂O), etc. are used as acleaning composition for cleaning a gate, a contact hole, a capacitor orthe like. However, these compositions easily corrode metals so thatthere is a demand for a cleaning composition which is unlikely tocorrode metals and which can remove a polymer derived from a resist, anative oxide and the like.

When a semiconductor device or a liquid crystal panel device such as ICor LSI is produced, the following steps are carried out. A photo-resistis uniformly applied to a film of electroconductive metal such asaluminum, copper, aluminum-copper alloy or the like or to an insulatingfilm such as SiO₂ film, each formed on a substrate. Then a resistpattern is formed by lithography technique, and the electroconductivemetal film or the insulating film is selectively etched. After etching,a residual resist is removed by ashing, by polymer removing compositionand the like.

Known polymer-removing compositions include, for example, thosecomprising an aqueous solution of a fluoride salt, a water-solubleorganic solvent such as DMF, DMSO or the like and optionallyhydrofluoric acid as disclosed in Japanese Unexamined PatentPublications No.197681/1997 and No.47401/2000. However, it is difficultfor a polymer-removing composition to satisfy two requirements, i.e. alow property of corroding a metal and a high ability of removing apolymer. Thus, conventional polymer-removing compositions remain to beimproved in the balance of the two requirements.

With increased complexity of element structure of IC and progress ofmulti-level interconnection, single damascene or dual damascene processis carried out in formation of interconnection. The damascene processincludes polishing (CMP: Chemical Mechanical Polishing) a surface of thearticle using an abrasive so that numerous particles derived from theabrasive adhere to the surface of the article after damascene process,and particles may become lodged in the surface of the film duringpolishing. After conventional CMP of oxide film, the article is cleanedwith a brush using a cleaning composition such as DHF(HF—H₂O), APM(NH₄OH—H₂O₂—H₂O) or the like. However, metals such as Al, Al—Cu, Cu orTiN exist on the surface of the article in damascene process. Thus theabove-mentioned cleaning composition is difficult to use because thecomposition is likely to corrode the metal surface.

DISCLOSURE OF THE INVENTION

An object of the present invention is to provide a cleaning compositionwhich shows a low property of corroding metals and an ability ofremoving a polymer, a native oxide and the like and which is usable forcleaning a metal gate, a contact hole, a via hole, a capacitor or thelike.

Another object of the invention is to provide a polymer-removingcomposition which can be suitably used in producing a semiconductordevice or a liquid crystal panel device such as IC or LSI and whichshows a low property of corroding a metal and a high capacity ofremoving a polymer.

A further object of the invention is to provide a cleaning compositionwhich can remove slurry particles from the surface of an article afterCMP in single damascene and dual damascene process and which shows a lowproperty of corroding metals or substrates of Al, Al—Cu, Cu, TiN and thelike which are likely to corrode.

The present invention includes the subject matters defined in thefollowing items.

Item 1. A cleaning composition comprising (1) at least one of fluoridesalts and hydrogendifluoride salts; (2) an organic solvent having ahetero atom or atoms; and (3) water.

Item 2. The cleaning composition according to item 1, wherein at leastone of fluoride salts and hydrogendifluoride salts is formed fromhydrofluoric acid and at least one member selected from the groupconsisting of ammonia, hydroxylamines, aliphatic amines, aromatic aminesand aliphatic or aromatic quaternary ammonium salts.

Item 3. The cleaning composition according to item 1, wherein (2) theorganic solvent having a hetero atom or atoms is at least one memberselected from the group consisting of N,N-dimethylformamide,N,N-dimethylacetamide, dimethylsulfoxide, N-methyl-2-pyrrolidone,1,3-dimethyl-2-imidazolidinone; methanol, ethanol, isopropyl alcohol(IPA), 1-propanol, 1-butanol, 2-butanol, t-butanol, 2-methyl-1-propanol,1-pentanol, 1-hexanol, 1-heptanol, 4-heptanol, 1-octanol,1-nonylalcohol, 1-decanol, 1-dodecanol and like alcohols; ethyleneglycol, 1,2-propanediol, propylene glycol, 2,3-butanediol, glycerin andlike polyols; acetone, acetylacetone, methyl ethyl ketone and likeketones; acetonitrile, propionitrile, butyronitrile, isobutyronitrile,benzonitrile and like nitriles; formaldehyde, acetaldehyde,propionaldehyde and like aldehydes; ethylene glycol monomethyl ether,ethylene glycol monoethyl ether, diethylene glycol monobutyl ether andlike alkylene glycol monoalkyl ethers; tetrahydrofuran, dioxane and likecyclic ethers; trifluoroethanol, pentafluoropropanol,2,2,3,3-tetrafluoropropanol and like fluoroalcohols; sulfolane andnitromethane.

Item 4. The cleaning composition according to item 3, wherein (2) theorganic solvent having a hetero atom or atoms is at least oneoxygen-containing organic solvent selected from the group consisting ofalcohols and ketones.

Item 5. The cleaning composition according to item 4, wherein (2) theoxygen-containing organic solvent is at least one member selected fromthe group consisting of isopropyl alcohol, ethanol and methanol, and theconcentration of water is 10% by mass or lower.

Item 6. The cleaning composition according to item 4, wherein (2) theoxygen-containing organic solvent is acetone and the concentration ofwater is 20 to 40% by mass.

Item 7. The cleaning composition according to item 1, which comprises(1) a fluoride salt represented by NR₄F (wherein Rs are the same ordifferent and each is a straight-chain or branched-chain alkyl group of1 to 12 carbon atoms which may be substituted with a fluorine atom oratoms, a phenyl group which may be substituted with a fluorine atom oratoms, or a hydrogen atom) in a concentration of 1% by mass or lowerand/or a hydrogendifluoride salt represented by NR₄HF₂ (wherein Rs areas defined above) in a concentration of 0.001 to 1% by mass; (3) waterin a concentration of 10% by mass or lower; and (2) at least one memberselected from the group consisting of isopropyl alcohol, ethanol andmethanol as the remainder.

Item 8. The cleaning composition according to item 1, wherein a fluoridesalt represented by NR₄F (wherein Rs are the same or different and eachis a straight-chain or branched-chain alkyl group of 1 to 12 carbonatoms which may be substituted with a fluorine atom or atoms, a phenylgroup which may be substituted with a fluorine atom or atoms, or ahydrogen atom) in a concentration of 1% by mass or lower and/or ahydrogendifluoride salt represented by NR₄HF₂ (wherein R is as definedabove) in a concentration of 0.001 to 1% by mass; (3) water in aconcentration of 20 to 40% by mass; and (2) acetone as the remainder.

Item 9. The cleaning composition according to item 1, which furthercomprises (4) at least one member selected from the group consisting ofan anionic surfactant, a cationic surfacatant, a nonionic surfactant andan amphoteric surfactant.

Item 10. The cleaning composition according to item 9, wherein (4) thesurfactant is an anionic surfactant.

Item 11. The cleaning composition according to item 10, wherein (4) theanionic surfactant has a sulfonic acid group.

Item 12. The cleaning composition according to item 11, wherein (4) theanionic surfactant is at least one member selected from the groupconsisting of a compound represented by C_(n)H_(m)C₆H₃(SO₃H)Oph(SO₃H)(wherein ph is a phenylene group, n is an integer of 1 to 30 and m is aninteger of 3 to 61) and a metal salt, an ammonium salt, a primary aminesalt, a secondary amine salt and a tertiary amine salt of the compound.

Item 13. The cleaning composition according to item 11, wherein (4) theanionic surfactant is at least one member selected from the groupconsisting of a compound represented by C_(n)H_(m)ph(SO₃H) (wherein phis a phenylene group, n is an integer of 1 to 30 and m is an integer of3 to 61) and a metal salt, an ammonium salt, a primary amine salt, asecondary amine salt and a tertiary amine salt of the compound.

Item 14. The cleaning composition according to item 10, wherein thecontent of (4) the anionic surfactant is 0.001 to 10% by mass.

Item 15. The cleaning composition according to item 10, which comprises(1) a fluoride salt represented by NR₄F (wherein Rs are the same ordifferent and each is a straight-chain or branched-chain alkyl group of1 to 12 carbon atoms which may be substituted with a fluorine atom oratoms, a phenyl group which may be substituted with a fluorine atom oratoms, or a hydrogen atom) in a concentration of 1% by mass or lowerand/or a hydrogendifluoride salt represented by NR₄HF₂ (wherein Rs areas defined above) in a concentration of 0.001 to 1% by mass; (3) waterin a concentration of 60% by mass or lower; (4) an anionic surfactant ina concentration of 0.001 to 10% by mass and (2) at least one memberselected from the group consisting of isopropyl alcohol, ethanol andmethanol as the remainder.

Item 16. The cleaning composition according to item 1, which ischaracterized by use for cleaning at least one of a metal gate, acontact hole, a via hole and a capacitor.

Item 17. The cleaning composition according to item 1, which ischaracterized by use for removing a residual polymer derived from aresist.

Item 18. The cleaning composition according to item 1, which ischaracterized by use for cleaning after CMP.

Item 19. A method of cleaning a semiconductor substrate having at leastone of a metal gate, a contact hole, a via hole and a capacitor formedthereon using a composition comprising (1) at least one of fluoridesalts and hydrogendifluoride salts; (2) an organic solvent having ahetero atom or atoms; and (3) water.

Item 20. A method of removing a polymer derived from a resist remainingon an article after etching or after ion implantation using acomposition comprising (1) at least one of fluoride salts andhydrogendifluoride salts; (2) an organic solvent having a hetero atom oratoms; and (3) water.

Item 21. A method of producing a semiconductor device, comprising thesteps of: forming a resist pattern on a work layer consisting of anelectroconductive layer on an insulating layer over a semiconductorsubstrate composed of silicon; forming the work layer into a specifiedpattern by dry-etching using the resist as a mask; and cleaning thesemiconductor substrate using a composition comprising (1) at least oneof fluoride salts and hydrogendifluoride salts; (2) an organic solventhaving a hetero atom or atoms; and (3) water.

Item 22. A method of producing a semiconductor device, comprising thesteps of: forming a specified pattern of an electroconductive layer overa semiconductor substrate composed of silicon; forming an insulatinglayer on the electroconductive layer; forming a resist pattern on a worklayer consisting of an insulating layer; forming the work layer into aspecified pattern by dry-etching using the resist as a mask; andcleaning the semiconductor substrate using a composition comprising (1)at least one of fluoride salts and hydrogendifluoride salts; (2) anorganic solvent having a hetero atom or atoms; and (3) water.

Item 23. A method of cleaning a treated surface after CMP treatment in asingle damascene or dual damascene process, using a compositioncomprising (1) at least one of fluoride salts and hydrogendifluoridesalts; (2) an organic solvent having a hetero atom or atoms; and (3)water.

Item 24. A method of producing a semiconductor device, comprising thesteps of: forming a work layer comprising an electroconductive layer andan insulating layer coexisting on one surface of a semiconductorsubstrate by a single damascene or dual damascene; and cleaning the worklayer using a composition comprising (1) at least one of fluoride saltsand hydrogendifluoride salts; (2) an organic solvent having a heteroatom or atoms; and (3) water.

The composition of the present invention is characterized by comprising(1) at least one of fluoride salts and hydrogendifluoride salts; (2) anorganic solvent having a hetero atom or atoms; and (3) water and can beused in cleaning a metal gate, a contact hole, a via hole, a capacitoror the like in the course of producing a semiconductor. This cleaningcomposition can be also used for removing a polymer remaining on a sidewall of a contact hole, a via hole, a capacitor, a metal gate, a metalwiring and the like, for removing a resist residue after ionimplantation, for removing a polymer remaining after dry etching in asingle damascene or dual damascene process, or for cleaning after CMP ina single damascene or dual damascene process.

(1) A fluoride salt and a hydrogendifluoride salt to be added to thecleaning composition of the invention is preferably at least one of themprepared from hydrofluoric acid and at least one member selected fromthe group consisting of ammonia, hydroxylamines, aliphatic amines,aromatic amines, and aliphatic or aromatic quaternary ammonium salts.

Examples of the hydroxylamine for use in forming salts with hydrofluoricacid are hydroxylamine, N-methlhydroxylamine, N,N-dimethylhydroxylamine,N-ethylhydroxylamine, N,N-diethylhydroxylamine, N-propylhydroxylamine,N-phenylhydroxylamine and like hydroxylamines mono- or di-substitutedwith straight-chain or branched-chain alkyl of 1 to 4 carbon atoms or aphenyl group.

Examples of the aliphatic amine are methylamine, ethylamine,propylamine, isopropylamine, butylamine, hexylamine, octylamine,dimethylamine, diethylamine, dipropylamine, diisopropylamine,dibutylamine, trimethylamine, triethylamine, tripropylamine,triisopropylamine, tributylamine and like aliphatic amines mono-, di- ortri-substituted with straight-chain or branched-chain alkyl group of 1to 8 carbon atoms; monofluoromethylamine, difluoromethylamine,trifluoromethylamine, perfluoroethylamine, perfluoropropylamine,perfluoroisopropylamine, perfluorobutylamine, perfluorohexylamine,perfluorooctylamine, di(perfluoromethyl)amine, di(perfluoroethyl)amine,di(perfluoropropyl)amine, di(perfluoroisopropyl)amine,di(perfluorobutyl)amine, tri(perfluoromethyl)amine,tri(perfluoroethyl)amine, tri(perfluoropropyl)amine,tri(perfluoroisopropyl)amine, tri(perfluorobutyl)amine and likealiphatic amines mono-, di- or tri-substituted with straight-chain orbranched chain C₁₋₈ alkyl group containing at least one fluorine atom;monoethanolamine, ethylenediamine, 2-(2-aminoethylamino)ethanol,diethanolamine, 2-ethylaminoethanol, dimethylaminoethanol,ethyldiethanolamine, cyclohexylamine, dicyclohexylamine, etc.

Examples of the aromatic amine are aniline, N-methylaniline,N,N-dimethylaniline, benzylamine, dibenzylamine, N-methylbenzylamine,etc.

Examples of the aliphatic or aromatic quaternary ammonium salt aretetramethylammonium, tetraethylammonium, tetrapropylammonium,tetraisopropylammonium, tetrabutylammonium,trimethyl(2-hydroxyethyl)ammonium, tetraphenylammonium and likealiphatic or aromatic quaternary ammonium hydrochlorides, hydrobromides,sulfates, nitrates and like mineral acid salts.

The hydrofluoride to be used in the invention is a 1:1 salt ofhydrofluoric acid (HF) with ammonia, hydroxylamines, aliphatic amines oraromatic amines, or is hydrofluoride salt of aliphatic or aromaticquaternary ammonium. Preferred hydrofluorides include a fluoride saltrepresented by NR^(I) ₄F (wherein R^(I)s are the same or different andeach is a hydrocarbon group which may be substituted with a fluorineatom or atoms; or a hydrogen atom). Specific preferred examples of thefluoride salt represented by NR^(I) ₄F include a fluoride saltrepresented by NR₄F (wherein Rs are the same or different and each is astraight-chain or branched-chain alkyl group having 1 to 12 carbonatoms, preferably 1 to 4 carbon atoms which may be substituted with afluorine atom or atoms; a phenyl group which may be substituted with afluorine atom or atoms; or a hydrogen atom).

The hydrogendifluoride salt to be used in the invention is a 1:2 salt ofhydrofluoric acid (HF) with ammonia, hydroxylamine, aliphatic amine oraromatic amine, or is hydrofluoric acid salt of aliphatic or aromaticquaternary ammonium. Preferred hydrofluoride salts include ahydrogendifluoride salt represented by NR^(I) ₄HF₂ (wherein R^(I)s arethe same or different and each is a hydrocarbon group which may besubstituted with a fluorine atom or atoms; or a hydrogen atom).Preferred examples of the hydrogendifluoride salt represented by NR^(I)₄HF₂ include a hydrogendifluoride salt represented by NR₄HF₂ (wherein Rsare the same or different and each is a straight-chain or branched-chainalkyl group having 1 to 12 carbon atoms; preferably 1 to 4 carbon atomswhich may be substituted with a fluorine atom or atoms; a phenyl groupwhich may be substituted with a fluorine atom or atoms; or a hydrogenatom), and ammonium hydrogenfluoride is more preferable.

A hydrogendifluoride salt (such as ammonium hydrogendifluoride) to beadded to the composition of the invention may be in the form of crystalsor an aqueous solution of hydrogendifluoride salt (such as ammoniumhydrogendifluoride). Alternatively, a stoichiometric amount of afluoride salt (such as ammonium fluoride) and HF may be added to thecomposition to form a hydrogendifluoride salt (such as ammoniumhydrogendifluoride).

The ammonium fluoride to be added to the composition of the inventionmay be in the form of crystals or an aqueous solution.

Examples of (2) the organic solvent having a hetero atom or atoms to beadded to the composition of the invention are N,N-dimethylformamide,N,N-dimethylacetamide, dimethylsulfoxide, N-methyl-2-pyrrolidone,1,3-dimethyl-2-imidazolidinone; methanol, ethanol, isopropyl alcohol(IPA), 1-propanol, 1-butanol, 2-butanol, t-butanol, 2-methyl-1-propanol,1-pentanol, 1-hexanol, 1-heptanol, 4-heptanol, 1-octanol,1-nonylalcohol, 1-decanol, 1-dodecanol and like alcohols; ethyleneglycol, 1,2-propanediol, propylene glycol, 2,3-butanediol, glycerine andlike polyols; acetone, acetylacetone, methyl ethyl ketone,1,3-dihydroxyacetone and like ketones; acetonitrile, propionitrile,butyronitrile, isobutyronitrile, benzonitrile and like nitriles;formaldehyde, acetaldehyde, propionaldehyde and like aldehydes; ethyleneglycol monomethyl ether, ethylene glycol monoethyl ether, diethyleneglycol monobutyl ether and like alkylene glycol monoalkyl ethers;tetrahydrofuran, dioxane and like cyclic ethers; trifluoroethanol,pentafluoropropanol, 2,2,3,3-tetrafluoropropanol and likefluoroalcohols; sulfolane and nitromethane. More preferred areoxygen-containing organic solvents selected from alcohols and ketones.Preferred examples of such solvents are methanol, ethanol, n-propanol,isopropanol (IPA) and like alcohols, and acetone, methyl ethyl ketone,1,3-dihydroxyacetone and like ketones. These organic solvents having ahetero atom or atoms can be used either alone or in combination.

When (2) the oxygen-containing organic solvent in the composition of theinvention is at least one member selected from the group consisting ofisopropyl alcohol, ethanol and methanol, preferably the concentration ofwater is 10% by mass or lower. When (2) the oxygen-containing organicsolvent in the composition of the invention is acetone, theconcentration of water is preferably 20 to 40% by mass.

When containing an alcohol as the solvent, usually the composition ofthe invention comprises (1) 0.001 to 1% by mass of at least one offluoride salts and hydrogendifluoride salts, (2) 89 to 99.989% by massof an alcohol and (3) 0.01 to 10% by mass of water, or preferably (1)0.005 to 0.1% by mass of at least one of fluoride salts andhydrogendifluoride salts, (2) 89.99 to 99.985% by mass of an alcohol and(3) 0.01 to 10% by mass of water.

More specifically, a preferred composition of the invention comprises(1) a fluoride salt represented by NR₄F (wherein Rs are the same ordifferent and each is a straight-chain or branched-chain alkyl grouphaving 1 to 12 carbon atoms, preferably 1 to 4 carbon atoms which may besubstituted with a fluorine atom or atoms, a phenyl group which may besubstituted with a fluorine atom or atoms, or a hydrogen atom) in aconcentration of 1% by mass or lower and/or a hydrogendifluoride saltrepresented by NR₄HF₂ (wherein Rs are as defined above) in aconcentration of 0.001 to 1% by mass; (3) water in a concentration of10% by mass or lower; and (2) at least one member selected from thegroup consisting of isopropyl alcohol, ethanol and methanol as theremainder.

When containing a ketone as the solvent, usually the composition of theinvention comprises (1) 0.001 to 1% by mass of at least one of fluoridesalts and hydrogendifluoride salts, (2) 59 to 79.999% by mass of aketone and (3) 20 to 40% by mass of water, or preferably (1) 0.005 to0.1% by mass of at least one of fluoride salts and hydrogendifluoridesalts, (2) 59.9 to 79.995% by mass of a ketone and (3) 20 to 40% by massof water.

More specifically, a preferred composition of the invention comprises(1) a fluoride salt represented by NR₄F (wherein Rs are the same ordifferent and each is a straight-chain or branched-chain alkyl grouphaving 1 to 12 carbon atoms, preferably 1 to 4 carbon atoms which may besubstituted with a fluorine atom or atoms, a phenyl group which may besubstituted with a fluorine atom or atoms, or a hydrogen atom) in aconcentration of 1% by mass or lower and/or a hydrogendifluoride saltrepresented by NR₄HF₂ (wherein Rs are as defined above) in aconcentration of 0.001 to 1% by mass; (3) water in a concentration of 20to 40% by mass; and (2) acetone as the remainder.

The composition of the invention may further comprise (4) a surfactant.Useful surfactants are at least one of anionic, cationic and nonionicsurfactants. Among them, an anionic surfactant is preferred.

Preferred anionic surfactants include those of carboxylic acid type,sulfonic acid type or sulfuric ester type wherein a hydrophilic group is—COOM, —SO₃M, or —OSO₃M (wherein M is a hydrogen atom, ammonium or ametal atom) respectively. Useful salts are salts of alkali metals (suchas sodium, potassium or the like) and like metal salts, ammonium salts,primary, secondary or tertiary amine salts and the like. Metal atoms maybe monovalent or divalent. Among them, anionic surfactants of sulfonicacid type are preferred.

Useful surfactants of carboxylic acid type include, for example,CF₃(CF₂)_(a)COOH, (CF₃)₂CF(CF₂)_(a)COOH, HCF₂(CF₂)_(a)COOH,CF₃(CF₂)_(a)(CH₂)_(b)COOH, CF₃(CF₂)_(a)CF═CH(CH₂)_(b)COOH,C1(CF₂CFCl)_(p)CF₂COOH {wherein a is an integer of 2 to 17, b is aninteger of 1 or 2, and p is an integer of 1 to 9}, and their alkalimetal salts, ammonium salts, primary amine salts, secondary amine salts,tertiary amine salts, etc.

Specific examples are CF₃(CF₂)_(a)COONa, (CF₃)₂CF(CF₂)_(a)COONa,HCF₂(CF₂)_(a)COONa, CF₃(CF₂)_(a)(CH₂)_(b)COONa,CF₃(CF₂)_(a)CF═CH(CH₂)_(b)COONa, Cl(CF₂CFCl)_(p)CF₂COONa, etc.

Useful surfactants of sulfonic acid type include, for example,C_(c)H_(2c+1)SO₃H, C_(c)H_(2c+1)O(CH₂CH₂O)_(d)SO₃H andC_(c)H_(2c+1)-ph-SO₃H {wherein ph is a phenylene group, c is an integerof 5 to 20 and d is an integer of 0 to 20};C_(n)H_(m)C₆H₃(SO₃H)Oph(SO₃H) {wherein ph is a phenylene group, n is aninteger of 1 to 30 and m is an integer of 3 to 61}, C_(n)H_(m)Oph(SO₃H){wherein ph is a phenylene group, n is an integer of 1 to 30 and m is aninteger of 3 to 61}; and their metal salts, ammonium salts, primaryamine salts, secondary amine salts, tertiary amine salts, etc.

Specific examples are C₁₂H₂₅O(CH₂CH₂O)₂SO₃Na, C₉H₁₉phO(CH₂CH₂O)₄SO₃Na,C₁₂H₂₅O(CH₂CH₂O)₄SO₃Na, C₆F₁₁phSO₃Na, C₉F₁₉OphSO₃Na,R″″CH═CH(CH₂)_(j)SO₃Na {wherein R″″ is C_(j)H_(m), C_(j)F_(m) orC_(j)H_(k)F_(l), j is an integer of 0 to 30, m is an integer of 1 to 61,k is an integer of 1 to 60, and 1 is an integer of 1 to 60},C₁₂H₂₅OSO₃Na, C₁₂H₂₅phC₆H₃(SO₃H)Oph(SO₃H), etc.

It is preferable to use, among the anionic surfactants given above, acompound prepresented by C_(n)H_(m)C₆H₃(SO₃H)Oph(SO₃H){wherein ph is aphenylene group, n is an integer of 1 to 30 and m is an integer of 3 to61} and a compound represented by C_(n)H_(m)ph(SO₃H) {wherein ph, n andm are as defined above} and their metal salts, ammonium salts, primaryamine salts, secondary amine salts, tertiary amine salts, etc.

In the formula given above, the group represented by C_(n)H_(m) is agroup which meets the requirements that n is an integer of 1 to 30 and mis an integer of 3 to 61, such as a straight-chain or branched chainaliphatic alkyl group, an aliphatic alkenyl group having at least onedouble bond, an alicyclic alkyl group which may have a branched chain,an alicyclic alkenyl group which may have a branched chain, an aromaticalkyl group and the like.

Preferred nonionic surfactants are surfactants of polyethylene glycoltype wherein a hydrophilic group is one represented by—R′(CH₂CH₂O)_(q)R″ or —R′O(CH₂CH₂O)_(q)R″ {wherein R″ is a hydrogen atomor an alkyl group having 1 to 10 carbon atoms, R′ is a hydrocarbon grouphaving 1 to 20 carbon atoms in which a hydrogen atom or atoms may besubstituted with a fluorine atom or atoms, and q is an integer of 0 to30}. Specific examples are as follows.

C₉F₁₇O(CH₂CH₂O)_(q)CH₃(q=0 to 30), C₉H₁₉ph(CH₂CH₂O)₁₀H,C₁₂H₂₅O(CH₂CH₂O)₉H, C₉H₁₉phO(CH₂CH₂O)₁₀H, C₉H₁₉phO(CH₂CH₂O)₅H,C₈H₁₇phO(CH₂CH₂O)₃H, C₈H₁₇ph(CH₂CH₂O)₁₀H {wherein ph is a phenylenegroup}, etc.

Examples of the cationic surfactants include primary amine representedby R′″NH₂, secondary amine represented by R′″₂NH, tertiary aminerepresented by R′″₃N, and tetraamine represented by [R′″₄N]M′ (whereinR′″s are the same or different and each represents a straight chain orbranched chain alkyl group of 1 to 30 carbon atoms which may besubstituted with a fluorine atom or atoms or a OH group or groups, or aphenyl group which may be substituted with a fluorine atom or atoms or aOH group or groups, or a hydrogen atom, and M′ is a monovalent anion(e.g. Cl⁻). Specific examples of the compound are:

CH₃(CH₂)_(n)NH₂, (CH₃(CH₂)_(n))₂NH, (CH₃(CH₂)_(n))₃N,(CH₃(CH₂)_(n))₄NCl, CH₃(CH₂)_(n)N((CH₂)_(n)OH)₂, CF₃(CF₂)_(n)NH₂,(CF₃(CF₂)_(n))₂NH, (CF₃(CF₂)_(n))₃N, (CF₃(CF₂)_(n))₄NCl,CF₃(CF₂)_(n)N((CH₂)_(n)OH)₂, C₆H₅NH₂, and (CH₃)₂(CH₂)_(n)NH₂, (wherein nis an integer of 1 to 30).

The content of the surfactant is not limited insofar as the contemplatedeffect of the invention can be achieved. Usually it is about 0.0001 toabout 10% by mass, preferably about 0.001 to about 5% by mass, morepreferably about 0.01 to about 1% by mass.

When an anionic surfactant is used, the content is preferably 0.001 to10% by mass.

When the composition of the invention contains an anionic surfactant,the content of water is preferably 60% by mass or lower.

When the composition of the invention contains an anionic surfactant,usually the composition of the invention comprises (1) 0.001 to 1% bymass of at least one of fluoride salts and hydrogendifluoride salts, (2)29 to 99.988% by mass of an organic solvent having a hetero atom oratoms, (3) 0.01 to 60% by mass of water, and (4) 0.001 to 10% by mass ofan anionic surfactant, or preferably (1) 0.005 to 1% by mass of at leastone of fluoride salts and hydrogendifluoride salts, (2) 58.0 to 99.975%by mass of an organic solvent having a hetro atom or atoms, (3) 0.01 to40% by mass of water and (4) 0.01 to 1% by mass of an anionicsurfactant.

More specifically, a preferred polymer-removing composition of theinvention comprises (1) a fluoride salt represented by NR₄F (wherein Rsare the same or different and each is a straight-chain or branched-chainalkyl group having 1 to 12 carbon atoms, preferably 1 to 4 carbon atomswhich may be substituted with a fluorine atom or atoms, a phenyl groupwhich may be substituted with a fluorine atom or atoms, or a hydrogenatom) in a concentration of 1% by mass or lower and/or ahydrogendifluoride salt represented by NR₄HF₂ (wherein Rs are as definedabove) in a concentration of 0.001 to 1% by mass; (3) water in aconcentration of 60% by mass or lower; (4) an anionic surfactant in aconcentration of 0.001 to 10% by mass; and (2) at least one memberselected from the group consisting of isopropyl alcohol, ethanol andmethanol as the remainder.

The composition of the invention may further comprise (5) a corrosioninhibitor. Examples of the corrosion inhibitor are catechol, pyrogallol,oxine and like aromatic hydroxy compounds, benzotriazole, tolyltriazoleand like triazole compounds and derivatives thereof, phthalic acid,salicylic acid, azelaic acid and like carboxyl-containing organiccompounds, ethylenediaminetetraacetic acid and like aminopolycarboxylicacids, 1,2-propaneaminetetramethylenephosphonic acid, and likephosphonic acids, cupferron and like chelating agents, pyridinederivatives, sodium 2-mercaptobenzothiazole and like thiazole compounds,tetramethylammonium formate and like tatraammonium salts, sorbitol,arabitol, amylose, and like saccharides and derivatives thereof. Thecontent of the corrosion inhibitor is not limited insofar as theintended effect of the invention is achieved. It is about 0.01 to about30% by mass, preferably about 0.5 to about 10% by mass.

The composition of the invention comprising (1) at least one of fluoridesalts and hydrogendifluoride salts; (2) an organic solvent having ahetero atom or atoms; and (3) water has a THOX or BPSG etch rate at 25°C. of 100 Å/min or lower, preferably 80 Å/min or lower, more preferably60 Å/min or lower, still more preferably 50 Å/min or lower.

The composition of the invention shows a low property of corrodingmetals and a substrate of Al, Al—Cu, Cu, W, Al—Si, Al—Si—Cu or the likewhich are likely to become corroded. Further the composition of theinvention exhibits an excellent cleaning ability in treating, at a lowtemperature for a short time, a polymer derived from a resist, a nativeoxide and contaminants such as organic substances and particles producedin the process of producing a semiconductor.

Consequently the composition of the invention can be used for cleaningat least one of metal gate, a contact hole, a via hole and a capacitorin the course of producing semiconductors even when a material for agate electrode contains a metal.

In the present invention, cleaning is performed on a substrate at anintermediate stage in the process of manufacturing semiconductors. Forexample, cleaning is carried out before embedding metal parts afterforming a contact hole.

Stated more specifically, the composition of the invention can be usedin the process of manufacturing semiconductors, namely in the followingsteps. A resist pattern is formed on a work layer consisting of anelectroconductive layer formed on an insulating layer over a substrateof silicon, i.e. a semiconductor substrate. Then the work layer isformed into specified pattern by dry-etching using the resist as a mask.Thereafter the obtained semiconductor substrate is cleaned with thecomposition. In these steps, for example, a metal gate and a metalwiring are formed on the semiconductor substrate.

Further the composition of the invention can be used in the process ofmanufacturing semiconductors, namely in the following steps. A resistpattern is formed on a work layer consisting of an insulating layerformed on electroconductive layer over a substrate of silicon, i.e. asemiconductor substrate. Then the work layer is formed into specifiedpattern by dry-etching using the resist as a mask. Thereafter theobtained semiconductor substrate is cleaned with the composition. Inthese steps, for example, a via hole and a contact hole are formed onthe semiconductor substrate. These steps correspond with dry etchingstep in a single damascene or dual damascene process.

In cleaning a metal gate, a contact hole, a via hole and a capacitorwith the cleaning composition of the invention, for example, an articleto be treated (such as a semiconductor substrate having at least one ofa metal gate, a contact hole, a via hole and a capacitor formed thereon)is immersed in the composition and treated, for example, at about 15 toabout 40° C., preferably approximately at room temperature for about 0.5to about 30 minutes. The cleaning can be performed by bringing thecleaning composition into contact with the article to be treated. Forexample, the article to be treated can be cleaned by supplying thecomposition onto the article while rotating it, by continuously sprayingthe composition over the article, or by immersing the article in thecomposition.

The semiconductor substrate cleaned with the composition of theinvention can be processed into various kinds of semiconductor devicesby conventional methods (such as the method disclosed in Atlas of ICTechnologies: An Introduction to VLSI Processes by W. Maly, 1987 by TheBenjamin/Cummings Publishing Company Inc.).

The composition of the invention shows a low property of corroding ametal and a substrate of Al, Al—Cu, Cu, W, Al—Si, Al—Si—Cu or the likewhich are likely to become corroded. Further the composition of theinvention exhibits a high cleaning ability in treating, at a lowtemperature for a short time, a polymer derived from a resist or thelike. Accordingly the cleaning composition of the invention can be usedfor removing a polymer for a resist remaining on a side wall of a viahole, a metal gate, a contact hole, a capacity or the like, namely canbe used as a composition for removing such polymer. The presentinvention also includes such composition for removing a polymer.

The polymer-removing composition of the invention can be used also forremoving the polymer remaining after forming a metal gate, a contacthole, a via hole, a capacitor or a n⁺ or p⁺ region or for removing thepolymer remaining after dry etching in a single damascene or dualdamascene process.

The polymer can be removed with the composition of the invention byimmersing an article to be treated (e.g., a semiconductor substratehaving formed thereon at least one of via hole, metal gate, contact holeand capacitor) in the composition for treatment, e.g. at about 15 toabout 40° C., preferably approximately at room temperature for about 0.5to about 30 minutes. In this case, the polymer can be removed bybringing the composition into contact with the article to be treated.For example, the article may be cleaned by supplying the compositiononto the article while rotating it, or by continuously spraying thecomposition over the article.

Preferably the composition of the invention is used for removing apolymer remaining on a semiconductor substrate having a fine pattern(e.g. a pattern having a gap of about 0.0001 to about 10 μm).

After a polymer has been removed from the semiconductor substrate withthe composition of the invention, the semiconductor substrate can beprocessed into various kinds of semiconductor devices by conventionalmethods (e.g., the method disclosed in Atlas of IC Technologies: AnIntroduction to VLSI Processes by W. Maly, 1987 by The Benjamin/CummingsPublishing Company Inc.).

The cleaning composition of the invention (especially polymer-removingcomposition) can be advantageously used for resists (including anegative type resist and a positive type resist) which can be developedusing an aqueous solution of alkali. The foregoing resists include (i) apositive type resist comprising naphthoquinonediazide compound andnovolak resin; (ii) a positive type resist comprising a compound whichgenerates an acid by exposure to light, a compound which decomposes dueto an acid and which is thereby increased in the solubility in anaqueous solution of alkali, and an alkali-soluble resin; (iii) apositive type resist comprising a compound which generates an acid byexposure to light, and an alkali-soluble resin having a group whichdecomposes due to an acid and which is thereby increased in thesolubility in an aqueous solution of alkali; and (iv) a negative typeresist comprising a compound which generates an acid by exposure tolight, a crosslinking agent and an alkali-soluble resin. However, theforegoing resists are not limited thereto.

After etching, a polymer derived from the residual resist may be cleanedor removed with the composition of the invention after or withoutashing.

The cleaning composition and the polymer-removing composition accordingto the invention can be used in the course of producing liquid crystalpanel devices as well as in the course of producing semiconductors.

In the course of producing semiconductors, cleaning is required forremoving an abrasive material from the surface of the substrate afterCMP in a single damascene or dual damascene process. Using the cleaningcomposition of the invention, the abrasive material remaining on thesurface of the substrate can be removed with a brush or the like afterCMP. Accordingly the cleaning composition of the invention can be usedfor cleaning the surface of the substrate after CMP in the course ofproducing semiconductors.

The article to be treated is cleaned with the composition of theinvention after CMP, for example, by immersing the article in thecomposition at about 15 to about 40° C., preferably approximately atroom temperature for about 0.1 to about 30 minutes or by allowing thecomposition to flow over the article at about 15 to about 40° C.,preferably approximately at room temperature for about 1 second to about10 minutes. Although a brush need not be used in the cleaning step, theslurry can be removed with higher efficiency by use of a brush. Thus,the use of a brush is preferable. The article may be cleaned after CMPby its immersion in the composition for ultrasonic cleaning (megasoniccleaning).

The foregoing cleaning can be performed after CMP on a work layerconsisting of an electroconductive layer and an insulating layercoexisting on one surface of a semiconductor substrate or a work layerconsisting of an electroconductive layer thereon, for example, after CMPin single damascene process or dual damascene process for forming a plugor wiring.

The damascene process may be also carried out, for example, in thecourse of producing liquid crystal panel devices. The composition of theinvention can be used in cleaning the article after CMP in a singledamascene process or dual damascene process during the manufacture ofsuch elements.

This invention includes a method of producing a semiconductor device,comprising the steps of: forming a work layer consisting anelectroconductive layer and an insulating layer coexisting on onesurface of a semiconductor substrate by a single damascene or dualdamascene; and cleaning the work layer using the cleaning composition ofthe invention.

The semiconductor substrate cleaned with the cleaning composition of theinvention after CMP can be processed into various kinds of semiconductordevices by conventional methods (such as the method disclosed in Atlasof IC Technologies: An Introduction to VLSI Processes by W. Maly, 1987by The Benjamin/Cummings Publishing Company Inc.).

BEST MODE FOR CARRYING OUT THE INVENTION

The present invention will be described in more detail with reference tothe following examples to which, however, the invention is not limited.

The etch rate of each oxide film was determined by measuring thethickness of the films before and after etching with an Auto EL-IIIellipsometer manufactured by Rudolf Research. The etch rates of thefollowing compositions were calculated as the difference in thickness ofa film before and after being etched at 25° C. divided by etch time.

EXAMPLES 1 TO 8 AND COMPARATIVE EXAMPLES 1 TO 5

The compositions having the formulations shown below were prepared bythe conventional method.

Example 1: NH₄.HF₂ (0.01 wt %), water (0.3 wt %) and IPA as theremainder;

Example 2: NH₄.HF₂ (0.085 wt %), water (0.3 wt %) and IPA as theremainder;

Example 3: NH₄.HF₂ (0.01 wt %), NH₄F (0.065 wt %), water (7.5 wt %) andIPA as the remainder;

Example 4: (CH₃)₄N.HF₂ (0.3 wt %), water (7.5 wt %) and IPA as theremainder;

Example 5: C₈H₁₇NH₃.HF₂(0.5 wt %), water (7.5 wt %) and IPA as theremainder;

Example 6: NH₄.HF₂ (0.085 wt %), NH₄F (0.11 wt %), water (7.5 wt %) andMeOH as the remainder;

Example 7: NH₄.HF₂ (0.085 wt %), NH₄F (0.11 wt %), water (7.5 wt %) andEtOH as the remainder;

Example 8: NH₄.HF₂ (0.04 wt %), NH₄F (0.10 wt %), water (3.5 wt %) andacetone as the remainder;

Comparative Example 1: HF (5 wt %), water (5 wt %) and acetone as theremainder;

Comparative Example 2: HF (5 wt %), water (5 wt %) and IPA as theremainder;

Comparative Example 3: Aqueous ammonia (0.29 wt %);

Comparative Example 4: Fluoric acid (0.5 wt %);

Comparative Example 5: HF (0.125 wt %), NH₄F (40 wt %), and water as theremainder.

Test Example 1 Metal Corrosion Test I (without a Surfactant)

A Cu test piece, an Al wafer, and a W wafer (each 3 cm×3 cm) wereseparately immersed in 220 g of the composition at 22° C. for 10minutes. Then, the concentrations of Cu, Al and W dissolved out in thecomposition were measured with ICP-MS and an etch rate was calculated.The results are shown in Table 1.

TABLE 1 Composition Al (Å/min) Cu (Å/min) W (Å/min) Example 1 0.1 orlower 0.1 or lower 0.1 or lower Example 2 0.1 or lower 0.1 or lower 0.1or lower Example 3 0.1 or lower 0.1 or lower 0.1 or lower Example 4 0.1or lower 0.1 or lower 0.1 or lower Example 5 0.1 or lower 0.1 or lower0.1 or lower Example 6 0.1 or lower 0.1 or lower 0.1 or lower Example 70.1 or lower 0.1 or lower 0.1 or lower Example 8 0.1 or lower 0.1 orlower 0.1 or lower Comp. Ex. 1 3.0 2.0 0.21 Comp. Ex. 2 7.1 3.2 0.14Comp. Ex. 3 110 9.2 0.33 Comp. Ex. 4 330 14 0.98

Test Example 2 Metal Corrosion Test II (without a Surfactant)

In the composition of Example 1 (NH₄.HF₂ (0.01 wt %), water (0.3 wt %)and IPA as the remainder), the concentration of NH₄.HF₂ was maintainedat 0.01 wt %, and the proportions of water and IPA were changed as shownin Table 2 (only the amount of water was shown and the remainder wasIPA). Under the same conditions as in Test Example 1, the concentrationsof Cu, Al and W dissolved out in the composition were measured withICP-MS, and an etch rate was calculated. The results are shown in Table2.

TABLE 2 Water conc. (wt %) Al (Å/min) Cu (Å/min) W (Å/min) 0.3 0.1 orlower 0.1 or lower 0.1 or lower 2.5 0.1 or lower 0.1 or lower 0.1 orlower 5 0.1 or lower 0.1 or lower 0.1 or lower 10 0.1 or lower 0.1 orlower 0.1 or lower 20 0.1 or lower 0.1 or lower 0.35 30 5 0.29 2.3 50 300.59 3.2 70 43 2.8 5.4

Test Example 3 Metal Corrosion Test III (without a Surfactant)

In the composition containing acetone as a solvent (NH₄.HF₂ (0.04 wt %),water and acetone as the remainder), the concentration of NH₄.HF₂ wasmaintained at 0.04 wt %, and the proportions of water and IPA werechanged as shown in Table 3 (only the amount of water was shown and theremainder was IPA). Under the same conditions as in Test Example 1, theconcentrations of Cu, Al and W dissolved out in the composition weremeasured with ICP-MS, and an etch rate was calculated. The results areshown in Table 3.

TABLE 3 Water conc. (wt %) Al (Å/min) Cu (Å/min) W (Å/min) 0.01 4.3 1.00.1 or lower 10 2.5 0.31 0.1 or lower 20 1.2 0.36 0.1 or lower 30 1.10.1 or lower 0.1 or lower 40 1.1 0.1 or lower 0.1 or lower 50 50 0.400.39 60 47 1.0 0.24 70 46 2.9 0.21 80 44 6.5 0.31 90 44 9.6 0.30 100 468.9 0.47

Test Example 4 Metal Corrosion Test IV (without a Surfactant)

Using the compositions of Example 1 and Comparative Example 5, acorrosion test was conducted in the same manner as in Test Example 1using TiN wafer, CoSi wafer, W wafer and TiSi wafer (each 3 cm×3 cm).The results are shown in Table 4.

TABLE 4 Composition TiN (Å/min) CoSi (Å/min) W (Å/min) TiSi (Å/min)Example 1 0.001 0.001 or 0.001 or 0.001 or lower lower lower Comp. Ex. 50.01 0.049 0.014 0.085

It is apparent from the results of Test Examples 1 to 4 that thecompositions of this invention have a low capability of corroding ametal, can be used as a cleaning composition for a metal gate, a contacthole, a via hole, a capacitor or the like and can be preferably used asa polymer-removing composition or as a cleaning composition to beemployed after CMP.

For use as a cleaning composition for cleaning a contact hole or thelike or as a polymer-removing composition, the composition needs tohave, e.g., a property of cleaning a polymer derived from a resistremaining on a side wall of contact hole. Consequently Test Examples 5and 6 were carried out to investigate whether the composition has thisproperty.

Test Example 5 Polymer-Cleaning Ability Test I (Without a Surfactant)

A resist pattern was formed in the conventional manner, the patterncomprising a positive type photo-resist of naphthoquinone/novolak resinon a silicon wafer having an Al wiring layer (comprising three layers,i.e., Ti/TiN layer-Al layer-Ti/TiN layer) deposited thereon. The siliconwafer having the resist pattern was subjected to dry-etching of metalaccording to the conventional method. Then, the remaining resist wasremoved by ashing with an oxygen gas.

The obtained silicon wafer having metal wiring on the surface wasimmersed in each of the compositions of Examples 1 to 8 and ComparativeExamples 1 to 4 at 25° C. for 10 minutes for removal of the polymer. Thewafer thus treated was rinsed with pure water. The results of cleaningthe ashing residue on the silicon wafer (polymeric deposits) and theoccurrence or non-occurrence of corrosion of wiring metal were evaluatedby SEM (scanning electron microscope) photographic observation. Theresults of cleaning the polymeric deposits were rated as “good” or as“incomplete” (2-level rating). The occurrence or non-occurrence ofcorrosion of wiring metal was rated as “corroded” or “none” (2-levelrating). The results are shown in Table 5.

TABLE 5 Occurrence or non- Results of occurrence of Composition cleaningdeposits wiring metal Example 1 Good None Example 2 Good None Example 3Good None Example 4 Good None Example 5 Good None Example 6 Good NoneExample 7 Good None Example 8 Good None Comp. Example 1 Good CorrodedComp. Example 2 Good Corroded Comp. Example 3 Good Corroded Comp.Example 4 Good Corroded

In Test Example 5, Al wiring was formed before the test. If the Alwiring can be cleaned, the composition can be used for cleaning apolymer of other metal materials.

Test Example 6 Polymer-Cleaning Ability Test II (Without a Surfactant)

A resist pattern was formed in the conventional manner, the patterncomprising a positive type photo-resist of naphthoquinone/novolak resinon a silicon wafer having an interlayer dielectric on its surface and anAl wiring layer (comprising three layers, i.e., Ti/TiN layer-Allayer-Ti/TiN layer) under the interlayer dielectric. The silicon waferhaving the resist pattern was subjected to dry-etching of oxide filmaccording to the conventional method to form a via hole. Then, theremaining resist was removed by ashing with an oxygen gas.

The obtained silicon wafer having the via hole was immersed in each ofthe compositions of Examples 1 to 8 and Comparative Examples 1 to 4 at25° C. for 10 minutes for removal of the polymer deposits. The waferthus treated was rinsed with pure water. The results of cleaning theashing residue on the silicon wafer (polymeric deposits) and theoccurrence or non-occurrence of corrosion of wiring metal were evaluatedby SEM (scanning electron microscope) photographic observation. Theresults of cleaning the polymeric deposits were rated as “good” or as“incomplete” (2-level rating) The occurrence or non-occurrence ofcorrosion of wiring metal was rated as “corroded” or “none” (2-levelrating). The results are shown in Table 6.

TABLE 6 Occurrence or non- occurrence of Results of corrosion ofComposition cleaning deposits wiring metal Example 1 Good None Example 2Good None Example 3 Good None Example 4 Good None Example 5 Good NoneExample 6 Good None Example 7 Good None Example 8 Good None Comp.Example 1 Good Corroded Comp. Example 2 Good Corroded Comp. Example 3Good Corroded Comp. Example 4 Good Corroded

In Test Example 6, a via hole was formed before the test. If thedeposits of via hole can be cleaned, the composition can be used forcleaning the deposits of contact hole.

It is clear from the results of Test Examples 5 and 6 that thecomposition of the invention has a capability of cleaning the polymer(resist) and shows a property of scarcely corroding wiring metal. Thusit is evident that the composition of the invention is suitable as acomposition for cleaning a metal gate, a contact hole, a via hole, acapacitor and the like. It is also clear that the cleaning compositionof the invention can be suitably used for removing a polymer remainingon a side wall of a metal gate, a contact hole, a via hole, a capacitorand the like.

Test Example 7 Etch Rate of Insulating Layer (Without a Surfactant)

Using the compositions of Examples 1 to 8 and Comparative Examples 1 to4, an etch rate of each film was determined by etching at 25° C. a testsubstrate having a thermal oxide film, a BPSG film or an NSG film formedon the surface of a silicon substrate. The results are shown in Table 7.The etch rate in the table is shown as Å/min.

TABLE 7 Composition Thermal oxide film BPSG film NSG film Example 1 1010 10 Example 2 20 20 20 Example 3 1.6 15 12 Example 4 2.0 4.1 3.5Example 5 3.9 8.5 7.0 Example 6 1.3 23 11 Example 7 4.8 35 24 Example 80.5 8 16 Comp. Ex. 1 3 250 3.6 Comp. Ex. 2 6 330 11 Comp. Ex. 3 — — —Comp. Ex. 4 30 260 45

It is difficult to measure the etch rate of a native oxide because it isvery thin. As clear from Test Example 7, an oxide film such as a thermaloxide film, BPSG film and NSG film which are thicker than a native oxidecan be etched. Accordingly it is evident that a native oxide which isthinner than these films can be etched and can be removed (cleaned). Itis apparent from Test Examples 1 to 7 that the composition of theinvention shows a lower property of corroding metals than cleaningcompositions conventionally used and can clean a native oxide, polymericdeposits and the like. Such composition can be suitably used as acomposition for cleaning a metal gate, a contact hole, a via hole, acapacitor and the like.

The results of Table 7 show that the composition of the invention canremove a polymer adhering to a thermal oxide film, BPSG film, NSG filmand like films without significantly deforming a via hole. It isapparent from Test Examples 1 to 7 that the composition of the inventionshows a lower property of corroding metals than polymer-removingcompositions conventionally used and can remove a polymer (deposit)without significantly deforming a via hole. Consequently suchcomposition can be suitably used as a composition for removal of apolymer remaining on a side wall of a metal gate, a contact hole, a viahole, a capacitor, a metal wiring and the like and as a composition forremoval of resist residue after ion implantation or for removal of apolymer adhered by dry etching in a single damascene or dual damasceneprocess.

The slurry used in CMP may adhere to the surface of the article to betreated or may become partly lodged in an insulating layer to be treatedwhen the layer is polished. In this situation, the slurry is usuallylifted off by slightly etching the insulating layer and is scrubbed offwith a brush. It is clear from Test Example 7 that the foregoing filmscan be etched with the cleaning composition of the invention. Thus theslurry can be removed (cleaned) when the composition of the invention isused as a cleaning composition after CMP. The composition of theinvention exhibits a low property of corroding a metal and can remove aslurry so that it is suitable for use as a cleaning composition afterCMP.

Compositions containing an anionic surfactant were prepared and thefollowing tests were carried out.

EXAMPLES 9 TO 28 AND COMPARATIVE EXAMPLES 6 AND 7

Compositions having the following formulations were prepared by theconventional method.

Example 9: C₁₂H₂₅C₆H₃(SO₃H)Oph(SO₃H) (0.15%)! NH₄F (0.22%) water (7.5%)and IPA as the remainder;

Example 10: C₁₂H₂₅C₆H₃(SO₃H)Oph(SO₃H) (0.15%), NH₄F (0.185%) water (15%)and IPA as the remainder;

Example 11: C₁₂H₂₅C₆H₃(SO₃H)Oph(SO₃H) (0.15%), NH₄F (0.185%) water (20%)and IPA as the remainder;

Example 12: C₁₂H₂₅C₆H₃(SO₃H)Oph(SO₃H) (0.15%), NH₄F (0.185%) water (25%)and IPA as the remainder;

Example 13: C₁₂H₂₅C₆H₃(SO₃H)Oph(SO₃H) (0.15%), NH₄F (0.185%) water (30%)and IPA as the remainder;

Example 14: C₁₂H₂₅C₆H₃(SO₃H)Oph(SO₃H) (0.15%), NH₄F (0.093%) water(7.5%) and IPA as the remainder;

Example 15: C₁₂H₂₅C₆H₃(SO₃H)Oph(SO₃H) (0.15%), NH₄F (0.093%) water (15%)and IPA as the remainder;

Example 16: C₁₂H₂₅C₆H₃(SO₃H)Oph(SO₃H) (0.15%), NH₄F (0.093%) water (20%)and IPA as the remainder;

Example 17: C₁₂H₂₅C₆H₃(SO₃H)Oph(SO₃H) (0.15%), NH₄F (0.093%) water (25%)and IPA as the remainder;

Example 18: C₁₂H₂₅C₆H₃(SO₃H)Oph(SO₃H) (0.15%), NH₄F (0.093%) water (30%)and IPA as the remainder;

Example 19: C₁₂H₂₅C₆H₃(SO₃H)Oph(SO₃H) (0.075%), NH₄F (0.185%) water(7.5%) and IPA as the remainder;

Example 20: C₁₂H₂₅C₆H₃(SO₃H)Oph(SO₃H) (0.075%), NH₄F (0.185%) water(15%) and IPA as the remainder;

Example 21: C₁₂H₂₅C₆H₃(SO₃H)Oph(SO₃H) (0.075%), NH₄F (0.185%) water(20%) and IPA as the remainder;

Example 22: C₁₂H₂₅C₆H₃(SO₃H)Oph(SO₃H) (0.075%), NH₄F (0.185%) water(25%) and IPA as the remainder;

Example 23: C₁₂H₂₅C₆H₃(SO₃H)Oph(SO₃H) (0.075%), NH₄F (0.185%) water(30%) and IPA as the remainder;

Example 24: C₁₂H₂₅C₆H₃(SO₃H)Oph(SO₃H) (0.075%), NH₄F (0.093%) water(7.5%) and IPA as the remainder;

Example 25: C₁₂H₂₅C₆H₃(SO₃H)Oph(SO₃H) (0.075%), NH₄F (0.093%) water(15%) and IPA as the remainder;

Example 26: C₁₂H₂₅C₆H₃(SO₃H)Oph(SO₃H) (0.075%), NH4F (0.093%) water(20%) and IPA as the remainder;

Example 27: C₁₂H₂₅C₆H₃(SO₃H)Oph(SO₃H) (0.075%), NH₄F (0.093%) water(25%) and IPA as the remainder;

Example 28: C₁₂H₂₅C₆H₃(SO₃H)Oph(SO₃H) (0.075%), NH₄F (0.093%) water(30%) and IPA as the remainder;

Comparative Example 6: C₉H₁₉phO(CH₂CH₂O)₁₀H (0.15%), NH₄HF₂ (0.01%),NH₄F (0.065%), water (7.5%) and IPA as the remainder;

Comparative Example 7: NH₄F (0.055%), water (10%) and IPA as theremainder;

Test Example 8 Metal Corrosion Test V (with a Surfactant)

A Cu test piece, an Al wafer, and a W wafer (each 3 cm×3 cm) wereseparately immersed in 100 g of each of the compositions of Examples 9to 28 and Comparative Examples 6 and 7 at 22° C. for 30 minutes. Then,the concentrations of Cu, Al and W dissolved out in the composition weremeasured with ICP-MS and an etch rate was calculated. The results areshown in Table 8.

TABLE 8 Composition Al (Å/min) Cu (Å/min) W (Å/min) Example 9 0.1 orlower 0.1 or lower 0.1 or lower Example 10 0.1 or lower 0.1 or lower 0.1or lower Example 11 0.1 or lower 0.1 or lower 0.1 or lower Example 120.1 or lower 0.1 or lower 0.1 or lower Example 13 0.1 or lower 0.1 orlower 0.1 or lower Example 14 0.1 or lower 0.1 or lower 0.1 or lowerExample 15 0.1 or lower 0.1 or lower 0.1 or lower Example 16 0.1 orlower 0.1 or lower 0.1 or lower Example 17 0.1 or lower 0.1 or lower 0.1or lower Example 18 0.1 or lower 0.1 or lower 0.1 or lower Example 190.1 or lower 0.1 or lower 0.1 or lower Example 20 0.1 or lower 0.1 orlower 0.1 or lower Example 21 0.1 or lower 0.1 or lower 0.1 or lowerExample 22 0.1 or lower 0.1 or lower 0.1 or lower Example 23 0.1 orlower 0.1 or lower 0.1 or lower Example 24 0.1 or lower 0.1 or lower 0.1or lower Example 25 0.1 or lower 0.1 or lower 0.1 or lower Example 260.1 or lower 0.1 or lower 0.1 or lower Example 27 0.1 or lower 0.1 orlower 0.1 or lower Example 28 0.1 or lower 0.1 or lower 0.1 or lower

It is apparent from the results of Table 8 that the composition of theinvention shows a low property of corroding metals.

The results of Table 8 show that the composition of the invention has alow property of corroding metals, can be used as a composition forcleaning a metal gate, a contact hole, a via hole, a capacitor and thelike, and can be preferably used as a polymer-removing composition andas a cleaning composition to be employed after CMP.

Such composition needs to have, in addition, a capability of removing aresidual polymer (resist). Consequently Test Examples 9 and 10 werecarried out to investigate whether the composition has this capability.

Test Example 9 Polymer-Removing Ability Test I (with a Surfactant)

A resist pattern was formed in the conventional manner, the patterncomprising a positive type photo-resist of naphthoquinone/novolak resinon a silicon wafer having an Al wiring layer (comprising three layers,i.e., Ti/TiN layer-Al layer-Ti/TiN layer) deposited thereon. The siliconwafer having the resist pattern was subjected to dry-etching of metalaccording to the conventional method. Then, the remaining resist wasremoved by ashing with an oxygen gas.

The obtained silicon wafer having metal wiring on the surface wasimmersed in each of the compositions of Examples 9 to 28 and ComparativeExamples 6 and 7 at 25° C. for 10 minutes for removal of the polymer.The wafer thus treated was rinsed with pure water. The results ofremoving the ashing residue on the silicon wafers (polymeric deposits)and the occurrence or non-occurrence of corrosion of wiring metal wereevaluated by SEM (scanning electron microscope) photographicobservation. The results of removing polymeric deposits were rated as“good” or as “incomplete” (2-level rating). The occurrence ornon-occurrence of corrosion of wiring metal was rated as “corroded” or“none” (2-level rating). The results are shown in Table 9.

TABLE 9 Occurrence or non- occurrence of Results of corrosion ofComposition removing deposits wiring metal Example 9 Good None Example10 Good None Example 11 Good None Example 12 Good None Example 13 GoodNone Example 14 Good None Example 15 Good None Example 16 Good NoneExample 17 Good None Example 18 Good None Example 19 Good None Example20 Good None Example 21 Good None Example 22 Good None Example 23 GoodNone Example 24 Good None Example 25 Good None Example 26 Good NoneExample 27 Good None Example 28 Good None Comp. Ex. 1 Incomplete NoneComp. Ex. 2 Incomplete None

It is apparent from the results of Table 9 that the composition of theinvention can remove the polymeric deposits on a wiring layer, and doesnot corrode the wiring metal.

Test Example 10 Polymer-Removing Ability Test II (with a Surfactant)

A resist pattern was formed in the conventional manner, the patterncomprising a positive type photo-resist of naphthoquinone/novolak resinon a silicon wafer having on its surface an interlayer dielectric on anAl wiring layer (comprising three layers, i.e., Ti/TiN layer-Allayer-Ti/TiN layer). The silicon wafer having the resist pattern wassubjected to dry-etching of oxide film according to the conventionalmethod to form a via hole. Then, the remaining resist was removed byashing with an oxygen gas.

The obtained silicon wafer having the via hole was immersed in each ofthe compositions of Examples 9 to 28 and Comparative Examples 6 and 7 at25° C. for 10 minutes for removal of the polymer deposits. The waferthus treated was rinsed with pure water. The results of removing theashing residue on the silicon wafers (polymeric deposits) and occurrenceor non-occurrence of corrosion of wiring metal were evaluated by SEM(scanning electron microscope) photographic observation. The results ofremoving the residue were rated as “good” or as “incomplete” (2-levelrating). The occurrence or non-occurrence of corrosion of wiring metalwas rated as “corroded” or “none” (2-level rating) The results are shownin Table 10.

TABLE 10 Occurrence or non- Results of occurrence of Compositionremoving deposits wiring metal Example 9 Good None Example 10 Good NoneExample 11 Good None Example 12 Good None Example 13 Good None Example14 Good None Example 15 Good None Example 16 Good None Example 17 GoodNone Example 18 Good None Example 19 Good None Example 20 Good NoneExample 21 Good None Example 22 Good None Example 23 Good None Example24 Good None Example 25 Good None Example 26 Good None Example 27 GoodNone Example 28 Good None Comp. Ex. 6 Incomplete None Comp. Ex. 7Incomplete None

It is apparent from the results of Table 10 that the composition of theinvention can remove deposits on an interlayer dielectric or in a viahole.

Test Example 11 Etch Rate of Insulating Film (with a Surfactant)

Since a via hole is formed of an oxide film, the shape of the hole iswidely changed by cleaning if an etch rate of the cleaning compositionis high. The following test was carried out to investigate the etch rateof oxide films using the polymer-removing composition of the invention.

Using the compositions of Examples 9 to 28, an etch rate of each filmwas determined by etching at 25° C. a test substrate comprising asilicon substrate having a thermal oxide film, BPSG film or NSG filmformed on its surface. The results are shown in Table 11. The etch ratein the table is shown as Å/min.

TABLE 11 Thermal oxide Composition film BPSG film NSG film Example 9 1529 24 Example 10 5.4 26 20 Example 11 2.0 23 15 Example 12 1.2 22 12Example 13 0.7 17 8.4 Example 14 3.5 25 14 Example 15 3.1 23 13 Example16 0.5 20 9.5 Example 17 0.3 18 8.4 Example 18 0.2 15 5.2 Example 19 5.317 17 Example 20 3.1 15 14 Example 21 0.7 14 10 Example 22 0.4 13 8.3Example 23 0.2 10 5.8 Example 24 3.8 10 6.9 Example 25 1.4 9.3 5.7Example 26 0.5 8.2 4.3 Example 27 0.3 7.8 3.4 Example 28 0.2 6.1 2.4

The results of Table 11 show that the composition of the invention canremove the polymer adhering to a thermal oxide film, BPSG film, NSG filmor like films without significantly changing the shape of via hole.

The results of Test Examples 8 to 11 show that the composition of theinvention shows a lower property of corroding metals than thepolymer-removing compositions conventionally used, and can remove apolymer (deposits) without significantly changing the shape of via hole.Consequently such composition can be suitably used as a composition forremoving a polymer adhering to a side wall of a metal gate, contacthole, via hole, capacitor, metal wiring and the like, or as acomposition for removing a resist residue after ion implantation or forremoving an adhered polymer after dry etching in a single damascene ordual damascene process. The composition of the invention has a lowproperty of corroding metals, can etch a native oxide, and can removepolymeric deposits so that it can be suitably used as a composition forcleaning a contact hole and the like. Further the composition of theinvention can be used also for cleaning after CMP because of itsproperties of rarely corroding metals and its capability of etching anative oxide.

What is claimed is:
 1. A cleaning composition consisting of: (1) atleast one of fluoride salts and hydrogendifluoride salts; (2) an organicsolvent having a hetero atom or atoms; (3) optionally, one or moresurfactants in an amount of from 0.0001 to 10.0 wt %; (4) optionally,one or more corrosion inhibitors, and (5) water.
 2. The cleaningcomposition according to claim 1, wherein at least one of fluoride saltsand hydrogendifluoride salts is formed from hydrofluoric acid and atleast one member selected from the group consisting of ammonia,hydroxylamines, aliphatic amines, aromatic amines and aliphatic oraromatic quaternary ammonium salts.
 3. The cleaning compositionaccording to claim 1, wherein (2) the organic solvent having a heteroatom or atoms is at least one member selected from the group consistingof N,N-dimethylformamide, N,N-dimethylacetamide, dimethylsulfoxide,N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone; methanol,ethanol, isopropyl alcohol (IPA), 1-propanol, 1-butanol, 2-butanol,t-butanol, 2-methyl-1-propanol, 1-pentanol, 1-hexanol, 1-heptanol,4-heptanol, 1-octanol, 1-nonylalcohol, 1-decanol, 1-dodecanol; ethyleneglycol, 1,2-propanediol, propylene glycol, 2,3-butanediol, glycerin;acetone, acetylacetone, methyl ethyl ketone; acetonitrile,propionitrile, butyronitrile, isobutyronitrile, benzonitrile;formaldehyde, acetaldehyde, propionaldehyde; ethylene glycol monomethylether, ethylene glycol monoethyl ether, diethylene glycol monobutylether; tetrahydrofuran, dioxane; trifluorethanol, pentafluoropropanol,2,2,3,3-tetrafluoropropanol; sulfolane and nitromethane.
 4. The cleaningcomposition according to claim 3, wherein (2) the organic solvent havinga hetero atom or atoms is at least one oxygen-containing organic solventselected from the group consisting of alcohols and ketone.
 5. Thecleaning composition according to claim 4, wherein (2) theoxygen-containing organic solvent is at least one member selected fromthe group consisting of isopropyl alcohol, ethanol and methanol, and theconcentration of water is 10% by mass or lower.
 6. The cleaningcomposition according to claim 4, wherein (2) the oxygen-containingorganic solvent is acetone and the concentration of water is 20 to 40%by mass.
 7. The cleaning composition according to claim 1, whichcomprises (1) a fluoride salt represented by NR₄F (wherein Rs are thesame or different and each is a straight-chain or branched-chain alkylgroup of 1 to 12 carbon atoms which may be substituted with a fluorineatom or atoms, a phenyl group which may be substituted with a fluorineatom or atoms, or a hydrogen atom) in a concentration of 1% by mass orlower and/or a hydrogendifluoride salt represented by NR₄HF₂ (wherein Rsare as defined above) in a concentration of 0.001 to 1% by mass; (5)water in a concentration of 10% by mass or lower; and (2) at least onemember selected from the group consisting of isopropyl alcohol, ethanoland methanol as the remainder.
 8. The cleaning composition according toclaim 1, wherein a fluoride salt represented by NR₄F (wherein Rs are thesame or different and each is a straight-chain or branched-chain alkylgroup of 1 to 12 carbon atoms which may be substituted with a fluorineatom or atoms, a phenyl group which may be substituted with a fluorineatom or atoms, or a hydrogen atom) in a concentration of 1% by mass orlower and/or a hydrogendifluoride salt represented by NR₄HF₂ (wherein Ris as defined above) in a concentration of 0.001 to 1% by mass; (5)water in a concentration of 20 to 40% by mass; and (2) acetone as theremainder.
 9. The cleaning composition according to claim 1, surfactant(3) comprises at least one member selected from the group consisting ofan anionic surfactant, a cationic surfactant, a nonionic surfactant andan aniphoteric surfactant.
 10. The cleaning composition according toclaim 9, wherein (3) the surfactant is an anionic surfactant.
 11. Thecleaning composition according to claim 10, wherein (3) the anionicsurfactant has a sulfonic acid group.
 12. The cleaning compositionaccording to claim 11, wherein (3) the anionic surfactant is at leastone member selected from the group consisting of a compound representedby C_(n)H_(m)C₆H₃(SO₃H)Oph(SO₃H) (wherein ph is a phenylene group, n isan integer of 1 to 30 and m is an integer of 3 to 61) and a metal salt,an aminonium salt, a primary amine salt, a secondary amine salt and atertiary amine salt of the compound.
 13. The cleaning compositionaccording to claim 11, wherein (3) the anionic surfactant is at leastone member selected from the group consisting of a compound representedby C_(n)H_(m)ph(SC₃H) (wherein ph is a phenylene group, n is an integerof 1 to 30 and m is an integer of 3 to 61) and a metal salt, an ammoniumsalt, a primary amine salt, a secondary amine salt and a tertiary aminesalt of the compound.
 14. The cleaning composition according to claim10, wherein the content of (3) the anionic surfactant is 0.001 to 10% bymass.
 15. The cleaning composition according to claim 10, whichcomprises (1) a fluoride salt represented by NR₄F (wherein Rs are thesame or different and each is a straight-chain or branched-chain alkylgroup of 1 to 12 carbon atoms which may be substituted with a fluorineatom or atoms, a phenyl group which may be substituted with a fluorineatom or atoms, or a hydrogen atom) in a concentration of 1% by mass orlower and/or a hydrogendifluoride salt represented by NR₄HF₂ (wherein Rsare as defined above) in a concentration of 0.001 to 1% by mass; (5)water in a concentration of 60% by mass or lower; (3) an anionicsurfactant in a concentration of 0.001 to 10% by mass and (2) at leastone member selected from the group consisting of isopropyl alcohol,ethanol and methanol as the remainder.
 16. The cleaning compositionaccording to claim 1, which is characterized by use for cleaning atleast one of a metal gate, a contact hole, a via hole and a capacitor.17. The cleaning composition according to claim 1, which ischaracterized by use for removing a residual polymer derived from aresist.
 18. The cleaning composition according to claim 1, which ischaracterized by use for cleaning after CMP.